/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2010 huliqing, huliqing.cn@gmail.com
 *
 * This file is part of QFaces.
 * QFaces is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * QFaces is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with QFaces.  If not, see <http://www.gnu.org/licenses/>.
 *
 * 这个文件是QFaces的一部分。
 * 您可以单独使用或分发这个文件，但请不要移除这个头部声明信息.
 * QFaces是一个自由软件，您可以自由分发、修改其中的源代码或者重新发布它，
 * 新的任何修改后的重新发布版必须同样在遵守LGPL3或更后续的版本协议下发布.
 * 关于LGPL协议的细则请参考COPYING、COPYING.LESSER文件，
 * 您可以在QFaces的相关目录中获得LGPL协议的副本，
 * 如果没有找到，请连接到 http://www.gnu.org/licenses/ 查看并获取副本。
 *
 * - Author: Huliqing
 * - Contact: huliqing.cn@gmail.com
 * - License: GNU Lesser General Public License (LGPL)
 * - Blog and source code availability: http://www.huliqing.name/
 */


package name.huliqing.qfaces;

import java.io.IOException;
import java.util.logging.Logger;
import javax.faces.context.FacesContext;
import javax.servlet.http.HttpServletResponse;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;

/**
 * 
 * @author huliqing
 */
public class Response {

    private final static Logger logger = Logger.getLogger(Response.class.getName());
    private static Response ins = null;

    private Response() {
    }

    public synchronized static Response getInstance() {
        if (ins == null) {
            ins = new Response();
        }
        return ins;
    }

    /**
     * 将信息以html格式向客户端输出.默认编码UTF-8
     * @param fc
     * @param text
     */
    public final void responseHTML(FacesContext fc, String text) {
        HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();
        response.setContentType("text/html");
        response.setHeader("Cache-Control", "no-cache");
        response.setCharacterEncoding("UTF-8");
        try {
            response.getWriter().write(text != null ? text : "");
        } catch (IOException ex) {
            logger.severe(ex.getMessage());
        }
    }

    /**
     * 将xml格式的Doc输出到客户端,默认编码UTF-8
     * @param fc
     * @param doc
     */
    public final void responseXML(FacesContext fc, org.w3c.dom.Document doc) {
        HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();
        response.setContentType("text/xml");
        response.setHeader("Cache-Control", "no-cache");
        response.setCharacterEncoding("UTF-8");
        try {
            XmlOper.write(doc, response.getWriter());
        } catch (TransformerConfigurationException tce) {
            logger.warning("TransformerConfigurationException:" + tce.getMessage());
        } catch (TransformerException te) {
            logger.warning("TransformerException:" + te.getMessage());
        } catch (IOException ioe) {
            logger.warning("IOException:" + ioe.getMessage());
        }
    }

    /**
     * 向客户端输出错误信息
     * @param fc
     * @param errorMessage
     * 		错误信息
     * @param status
     * 		服务器错误状态，如果为null,则使用500输出
     */
    public final void responseError(FacesContext fc, String errorMessage, Integer status) {
        HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();
        response.setContentType("text/html");
        response.setHeader("Cache-Control", "no-cache");
        response.setCharacterEncoding("UTF-8");
        response.setStatus(status != null ? status.intValue() : 500);
        try {
            response.getWriter().write(errorMessage != null ? errorMessage : "");
        } catch (IOException ex) {
            logger.severe(ex.getMessage());
            ex.printStackTrace();
        }
    }
}







